Development of humanoid robots is under progress. Advanced operations are required for the humanoid robot, such as coming into contact with people, autonomously avoiding obstacles, and grasping and moving an object. Since a touch sense is necessary for such operations, the research for providing the touch sensors to the robot hand and the entire body surface has been proceeding in recent years (for example as in PTLs 1 to 6).
Conventional touch sensor systems mainly adopt the mesh structure. For example, electrode lines are formed to each of the two electrode sheets. Then, the meshed wiring is formed by disposing the electrode sheets opposite to each other so that each of the electrode lines perpendicularly intersects. A pressure-sensitive conductive member is sandwiched between the two electrode sheets or a touch sensor element is disposed on each intersection of the electrode lines. Each touch sensor element converts a change in pressure or temperature caused by the contact with the object into an electric signal change according to the amount of the change.
The control unit is connected to each electrode line and centrally manages the plurality of touch sensor elements. More specifically, the control unit selects each touch sensor element in order and samples a sensor value of each sensor. In the control unit, the electric signals from the touch sensor elements are accumulated and data processed. Periodical repeating of such sampling operation detects whether the robot is in contact with the object and further which sensor is in contact. Then, it is possible to sense what position and what extent of strength the robot is in contact with the object.